as we come on the air the investigation is widening in the general david petraeus scandal and now it includes another general. general john allen, entrusted with nothing less than winding down the nation's war in afghanistan. you should know at any given moment there are fewer than 50 four-star generals around the globe for the united states, and they are the elite of the elite. tonight, two of the most formidable, one active duty, one retired, are in the heat of the spotlight and martha raddatz tells us what happened today. martha? >> reporter: diane, the consequences of dave petraeus' infidelity are astonishing. the nation is left without a cia director and the commander of our forces in afghanistan caught up in this bizarre web, as well. it is breathtaking. within days, two four-star generals so widely respected in the midst of scandal. first, david petraeus and now general john allen being investigated for sending what the pentagon said were "potentially inappropriate" messages, putting on hold his likely promotion to become the supreme allied commander in europe. >> of course, i